SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fded202cf390cbd9907e654806da9b35e1486470b3e80d2ddf4a84970af6b509' 
  AND token = 'CzAzLtpm6noigc6AJAoni907HiZXCFp7UtGyJBPBO1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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