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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27568b556cbe52b5da8991ee4ddeceb74bad0b6f69bf13c6e42e2df914adac2a' 
  AND token = 'gthwjw3+acg67NScUBMf11hIZ7V9kUhPpWYp30/iv+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}