SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3419e35d3f989fecfae867161b6012afe34d82bf0c4e33e7e3edcd74bda751cb' 
  AND token = 'nUfjoZ/Kli1cEG5+Mnq5bQHYH2XujiUSic2LLoATt4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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