SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a56c88fcfa5a296041022a83093f41fd0e0ba8ee6c0b36bc0f01b8d6a9c71167' 
  AND token = 'q7gFuHlu0VioNPJ4dlnJn/cs1S5HCDmCSbnaSppT1dw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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