SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4a36763711fb2f0f3ce2072c3969f59ba0be64db28f9b2127b8823a359d6949c' 
  AND token = '2gKOTiDXq2vgYS7j52zSpMAZGCLSCwxRuRlIerQ+1MU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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