SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83324c41758bf572f890d240502836b48915d6157b4a0686f6ca2c85facb4442' 
  AND token = 'P8fb4ZJIai2Q+JLcmnKbscSo0E1ZiQW9xoHLVYYWPKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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