SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8830183c7835421e994d3365cb5549d6a61221b7349eb33c082423d28fa6e862' 
  AND token = 'PoPE2rOwTxbDxwduHi3DEegTXbqAFNgRa81qC9e/hmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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