SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '260795eb3e5cff1285bab6f81a66e5e665417b7526e68d289db5e67d611b0dba' 
  AND token = 'Zk/W8Pe1CjCtcLHEis19PlnZ15tvDy5aVRrDBrJk9Gs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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