SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a09efac7b887e66317faaa02b2d05c292dcd6dae3dbec62f98ffb4c814caeda3' 
  AND token = 'X1okaM32zO/BcfgrzLp+yfcw6AdaYM+MS9ysGB5aGvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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