SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5369f9871a7230f6a6cb77a5601b6cf1694ccbd0965d57c6d234b86989f5d688' 
  AND token = '7ZTA9PyT8zIJ/G+NxnTeJn9xQqj4d1JkmgGoVTIZGXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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