SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9e966db5557d853ca1f9991ad7995c48e85533b6dedbb2ec2c39f9f7f424e1b' 
  AND token = '0JfCz5tEU/+j/kShCE+vqu5lgajIxhrQQRNwZdR7tFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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