SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bfe8c27f571a21068176fdffd5d79744b922b9c066e723800128df5fc6217ba' 
  AND token = 'BzjVJdtUjHJJqyBp3s9AiKd7OMW8rgVrWWuhIglp7AE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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