SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7eb109302a172fc91bbac6867e6b6a9ef88c87c545a8109c431cb9a26c89521' 
  AND token = 'ghiCUBVv+t4MHWJqNPXInBru8Kgp4Q/jUAIB+nsLyro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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