SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1a0ed4133d011fec3ff6942faa6a4dc063fd31614cf7ab5f9e9e8137fbdfb3d' 
  AND token = 'QiUQAhUtpEJYZQx7spTGta3F5WoowFBIGTqPBOawDTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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