SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03de05da5b69c5a210f0dbbbe6a027432170042ac3adccd58b7df34eb17d0c79' 
  AND token = 'CqJqjpyezs24052iyEpjGTvl8/wHUZkxQ42I08TYU3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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