SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7281a5e5212e8f1cca120897c86d4d7ccfa37741bfe68bd39be83d92abc11e8' 
  AND token = '1NphEGKGnxgLDJRNGCDVTa4mzMNyw3LjB+qerO41lag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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