SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad370c764b544cbfc4210a2afc6b4ec9c4c48b8464e42a7c209bda980c4db577' 
  AND token = 'fcowCHCXM/dUGieEHDXboIxis3ZxMPR8YOMMqmapZLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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