SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '604cb55a185201a565f53333100cc24a1e721d8fae459e3e5d7f353edb522f8c' 
  AND token = 'cI0lcpKCC7EMAuy8L2prUQmJstBptijqltgbcGAgMLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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