SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cadaac4b7eb668745f52656b0af095ccf0eb1e71a4f5f8074138232bf226785e' 
  AND token = '5CrMANPKQClgB7K1uHxmpkRK5ARjwtXEj/YJlJ1SKSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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