SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77d6f00886d9050d03c23c615e14f4386793b8ca93ac61feca93a23900116b26' 
  AND token = 'YPLcpxjZLhypOsKckEYX2FRwWI+jyIVttIhGQQ1gQzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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