SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9e884caa1f4b4ebfef3ccad4ad6cc9f03717b252e6b0a9b56e949bce20909d4' 
  AND token = '3pzuaM4MsoijgNu+WwJiYhRUKVgR0VtZVDIx6f/+QoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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