SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de4029ab7889299e0b4f65b3c276c67d62b620c59e9ec26ca8d034c56eb1fe48' 
  AND token = 'QobJBgqOur92IEypMAEzF9UjZpvGvTSn1hvpS5ofTUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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