SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '492266448902a41563b915eb6df741e415c865fe2d2659b771b66d372792f16c' 
  AND token = 'Jp7F0+CswDYOGVLrF1JtwoXkaZqzvoC7AnRsN1IlmOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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