SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '424659f0a7eaaeb6679f11efbf3572b91e7affaaf1c712b49d98b724a67083bd' 
  AND token = 'aHQ55FS//NNrBIMZkQIhy7Ft8Sa5L8RO57vz+Yt7eMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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