SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a6b2f1dbf99bcdb6b9c937d1e35d10425cccfcac017ccd27d5d8c4d09be4d23' 
  AND token = 'RmalQO++oINac0hfjIfbjTKIUsz31Z/EBUQowHrccq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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