SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe6c9f149b8cdf361072a5a948ff34ffb6d656def0702241c680309d737167e4' 
  AND token = 'aib3vgNgM/S6OxoUAU2bwORWrSpYDXlmisc/UsJBPNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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