SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '486075845f9fc57b0920ca5e3cd47dbe33440f832416bcc202ff65e9d0599c1b' 
  AND token = '0AlhdBct6nBlnWl5Z4MC2Xj4UgVwrxAjUx6n05etUmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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