SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad0e3bfd01dfb310d1a894e150fcfd12c50cdfc704be3b1e7253fe9c7b213012' 
  AND token = 'ALZqTMbr9BcKrvygsfkZozQvSvY1DT7lRwVH39YQY5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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