SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc41900982273993d4df7ef8fa77cae9f62cce9a6052fed21845cf13dc50d3b2' 
  AND token = 'B3K1cQORlHAxBJn+3Nl/zcTlqXKmONERtPdcj96vwZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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