SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49bbd25bfb8b454a3a33f3e7a7fdd449373fb2961797625878d21bb923300495' 
  AND token = 'gHhu3LS5/3NpcwaqKkMRUoetkAvhP1DvdeJ9IXsr0Yk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}