SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f4fdb183723dcb53fb2e2b18ce31da8c8d076e269cd6073efccc9987a193979' 
  AND token = 'buvzVpESc8oLbgGNiT9O+RHcyE7+7S0JOBoSDrZatUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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