Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8d7a231be405651102bc85c83a897e9e0e7a4d82891bb10a554e53d258ca051' 
  AND token = 'nw3loOftPpPcMmr67JoviBkNlkFYy/8TsCgyw4ntkn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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