SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a25ae4811e9d0ff44741b1f63bc7e4a59d5207256ad149bd330594c643db231d' 
  AND token = 'Y2gZrTZvE0/FqeRJfgNVjA9e+uJuWkusUqZpzp/9KYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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