SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '370a29f53ffcaff9be5e80697ac23a6591fd03e3945ec5c7df664770691e07e2' 
  AND token = 'w+w86BBi6QztOCFyjIeNJNQh9hWSJFjO98MCiXNckkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}