SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8be0bb5acf651a8449d9c2d6446427b102e9bed0c4fd47bbcaa6d34a90d74d1' 
  AND token = 'IaDSx96N/uBVknzOORFBLHHCOv8oz1oQUKd/9bqIdyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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