SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '311d193bdbcb1a9220b66c8e2c4c59a68310e453a7e849874146f4bfc2989d77' 
  AND token = 'QjYJhe8CCVfXp2J28tPa+innvgBBibCYTxfhTX7oMGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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