SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1e68dab95851722354a96ca4ee16e0164e853dfe28f2deb2254857ad1df861ac' 
  AND token = 'yLDoSsT766F+e8tPJvTf4JgLWZm7ax9YUKbSkWcHwYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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