SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffce25937eeb01b04b92ccf505168cf4574aa22f87878be0fceb2e103d209f60' 
  AND token = 'hvmzlSQkP7o/Ht0ZEFvz1XzwqzypEO0WcT6eIW2aDDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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