SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a31c5dd93e7b55d8b735c0d571ec5d78b225274839bf13f60876df8c8f43eab7' 
  AND token = 'UV/DYYF+qnqDaVZ0walOH3LTIn8jygBHOS+D0ST/cNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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