SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f73a28b603e76e576170c266c47b776210d6638fe315f229063b0cfa2084aa9' 
  AND token = 'EfQGq5ziTWjChtbiYJUd25XiLzoVULFzuqDvHONGxWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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