SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2b7fd33e4f844dc6632862390b495b4faaf1189668e068c20d906657a68d969' 
  AND token = 'EmRnB249IVIErBdGLGUoFafse8K6lanC8DRkCDTkdqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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