SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb045505cebe77032a4ff2889b6674007e30ecc338a46e6d95237aa4d1c57bd1' 
  AND token = '7U50NSUtIwMNmHjN1eYgXwAmU81+3Ev9KEvNtLH6pQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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