SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e798d2d72ea182fca995c925338b1bd6807026b8c886da08b1f10e3e6c5286da' 
  AND token = 'auEb5BVTgdU/W6VOxOSr1WOQqKwy+lwCAgowe60Tb/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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