SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7b41b908a7a8c8615f9f3be91163caefa000c8a13cf0a837a7d5b90912202ac' 
  AND token = 'DSz16B5hrKvdNu/sJxfmIBvonmSq/+yV/Xcoay6TaZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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