SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '010ef4808de5edae638a55115bbf6a5234be43d519331c162aed84d49fdb4aac' 
  AND token = 'j3tdNnRph8mEpORhv7DzsrTjzvj2sh1QoT9lLE7f/B8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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