SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71a56318488203ab8a73379aef59b1085097df537b5a5fc7ec969f7bd4116a41' 
  AND token = 'rnDZqeVpHWNIOOl/Hm6FZfRX9hmWyDzXBFla0bsLzkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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