SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70eaa33d4ece9962275ac0fa227e316095203d40d1685a02ecb00e7387480842' 
  AND token = 'KnLkGTc/FXVqa1YwekmIjidrkcnr+8gzaorS7+SsA+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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