SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a308ee8fa508bd65b94978b2a4860b6b784a21a212cee20d0846b867961168fb' 
  AND token = 'BY1lWhzsnzVSFV5kP+LAIIWPHcsbPAjwLPDnjKceVjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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