SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54d289a7b75350c3998440f2aa75360b7d481f17ecd54278081583b063675b0e' 
  AND token = 'm4AoZLDWvgMMeZHOtM/5KHWmenzTvpUkwodlF/d+VeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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