SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f120424bfefb2b59e3ca3bb60a732dc67226fd865d0973763880e67dd24b914d' 
  AND token = 'u88BlIMnanwDGqu3cYf3qLzjmLukauYgf8hKcQvatRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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