SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e7d1a6e17deb088f3abeb9dc5a732764f7ed4bd50fa5bf0da35689eaf8b6c91' 
  AND token = 'XczVKndZyYvS03Kdi8K3KdXxB4nTaEWRkYt0HPxkyBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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