SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'eec38041c0fb13ff6e6c97808fdd6f9fcb677864b03da3ca425b27c43727f599' 
  AND token = '+XPX5CxZ4TgzYVVJqDCBKrYj15Fwn6/2SzAl2BV6Dus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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