SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7027840999e8e9b3603af5fb5c48df3b2e1fc3eddaad4ab4bc9e0c63c448c785' 
  AND token = 'Z/onMJwrpLBc9J4fz7eH56MPKhY2Y8maEXAuDVI3wDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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