SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd1e5d463bcf682668a848d12d9151564b3cf3199e57037fb215331eda6e67e7' 
  AND token = 'ZEIN/Pmc5nDnzsie1uHbxXoMQllZz/EBFoe7hEktQ0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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