SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0e1c2a91addc8fb0d2ffd1d21697ef78c6f8759d2ddd6451c5ef4d0a4be3a474' 
  AND token = 'SdXFoHxwrf0Vul4YXo1SAXkHnpEyirEVV9vrIZknyXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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