SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '982987c171907b7e3c509bf705769da0424b3cca141795b56d443bb8ea77d0bf' 
  AND token = 'JLXUsbXKX7r0GWskNsiCzDG41IE0LrFrTjzUr62qn9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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