SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7301d47d9317b27a9c81f33aa95afbdce4ed9578e0f62ad87c3362f4ff93e61' 
  AND token = 'wxbFGReymqY8A/AkJplZjIugzFXzBu0zBITHHFvuCAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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