SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2abfa297962d2572835a7004dbf36912973dd041c4d6d57f299d4201ab4eb2ff' 
  AND token = 'w9KjvyafhYfu78UquMsJyPGncxWRoJAGSyz8Et2Vk5s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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