SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8dc9e8af2dba5277a453f8b88d70dee54f1d8f9c455f69efc259c6fa147615d' 
  AND token = 'B6TGE2rvPQm+lC/3mJSbDyMAyHYbvlLwYkzuO23xN28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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