SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '03ec57de73634e51cdcb6e3b3d37ba95163ec31fc31e746fadff76dc9d40fbe3' 
  AND token = 'oYUYST4OdSA1STtvAdIHY0VYFPquse0TSLhslCttcH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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