SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1aef501af9c4f0eb386810f41dba393f33220d329d8f2685697fa1f70422a24' 
  AND token = 'YJERCYOMQUs0N2QCU1JiTxNfmtVXh1LJi46KqR9KcVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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