SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5851ff963fe8112b28d349ea5d98dd150835d826b1f29f0677c62aefbbf0de93' 
  AND token = 'ApoGF3IIalNtzP/sqKjj7Z/3PrTMgAzYneIPzjcmtG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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