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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4e993864561152d918fb8b5d4638f9664ab2440e1faa0d1e37217ec4ee56a27' 
  AND token = 'X35bLEjDRdKbOqRx/SDmCOdRbdhRNEcH1UQd2ZVp0WU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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