SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17dc08bb09bc0f3dc581d18156536f48d6967dec5eeaed9d8198d44f2beda7eb' 
  AND token = 'Y0TKYxCxH7Xx8q5HxTAkGJLVncCoB4xDCwM2JvpCZxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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