SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c42f874ecdba51fdf38cdfb98ee13d10171c96ebf2548a762a81118f48d350c' 
  AND token = 'ZhB4lktXetKCr0vH0CI5CsKdMZaAuq6FAAXzOIOB11U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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