SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd43acd7684298aacc65d11d3b96145dd5dd0587bdf2f04b6f5202d669be45009' 
  AND token = 'QIU7Ny9dQKeWuSzzutPw6WoX7bipkDl5uYb0cixTVvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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