SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a736b7d689f7bddc6b1c8f76ac37aac6f4f0cad74b989d9de72fb1cef972daf' 
  AND token = 'NMoMRlhkRZwKU+4lf+jJXzj9B1sdcrPuRwfuwTB77Dg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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