SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea9b1d06e511ef09b9c78b7b65abf4749e6760678df5889141fb5854fba04a13' 
  AND token = 'LGiOOUXJih2zYP2FVclX5optIuqRjRJTpbyz3C/ZZbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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