SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '71a4c01534a27c0ca0acc3f1f7de9291ba60493fe7bcec5253324a895c9c1e0c' 
  AND token = '35BBWs1qGyN4Snw7TSt9R8rZ27HE3aH+KoaBjLyKvmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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