SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e685e32ca76d1180d7b10e76387b472aa2fe39ff61c1397a9d6d2e451345c49b' 
  AND token = 'VNmi45w6oPMebyJRm2ftZxE6OsZ5HZ1XHT2HrrcAiUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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