SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cad506a59a7c5c36a9084ccbf8b183ce09002a7f8385f1d36f475e4692395e0d' 
  AND token = 'BH3BxB3M2XvXXyxKOMeohpacUenr/tGCfpARCl2+2Zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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