SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45f831eadcb0f29984cfbfa7fc2c40dead207fbf73d1d9ac339374974d1629da' 
  AND token = 'ocD5TQhuc5nzw+YNYQw8rvDuuq2bofJN07lKuDT85CI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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