SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '181a2ac7dcf704a0beab7101e95cb2a96fbcd251fadf3b8749414c18eb03a4cf' 
  AND token = 'PECNFGNowd2v7MhxXtoaKZ98GfbWCsRwx8jGTkhyVDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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