SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24c47c7d6067555631647b3b25106192ef017ad8a8a745ce19185322e3838a88' 
  AND token = 'MoQNL34BGMUySvfGd0//5vS0k4szqknX2PJt5x58w3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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