SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c714a943d2bf9ffb9133b69fcd0ff144a651f489df70bd8025eec745e2c1223b' 
  AND token = '0esJwaU+OI/GjkIQ6ipoALFvk2+2ikWUfaZgvHZY+UI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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