SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cff0f8b1572c98cd5341de27ed024ee3c7a82af124eba9fff6943dda1bdb75b7' 
  AND token = 'qmuMeacv2fSofpO0u0r2naUuwkJ0HwCixKfNurjA0Mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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