SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '935bf9368e069eae45f4259f01d26f71ad5053a2be8c968e2924e831ec079dde' 
  AND token = 'NND/kI5XeJZlvWbc3SJdyli7mCMGBTuS69Y5kRyTcOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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