SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f82a857eb3e3812a254369cd426f6230e8177f5c8c03842b363542dac59fb84' 
  AND token = '2R9K/cQRx8c0ap/1mRBir1Iw2H7NhrdUxuqyOw8RfXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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