SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44dbde004451dc2cc02c19e9e77971e53e225fe41fd27be15b50c88fb09a66b0' 
  AND token = '1FILh1DWl0Aksvjg2bd7u4NhJiz0bZ79ubGBXTkrxJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}