SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c07c4eb4f57786a0b2a9b526f9d9d1a2c58f87af11012a8338921e84e6683ad' 
  AND token = 'OIzZhkSo60jW7gVKAUpgJPIh+0mSkd1+cRAJ/Ez9eeQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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