SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '365cf0fe119a84c442210fc199d28e3e55e9ace005867b727cb32be9059ab573' 
  AND token = 'L0LI0NWE4ywf1Umh0xy1UVZsfZxednk8y42wY4pDVSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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