SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb0e83285c1d3158e9c889a1f1a0f46c2d5fadaa8c6f978abeb13b92ba62863d' 
  AND token = 'jRJegqLMRtk9ASNb6QDg5upAmJEFTZYaHkaknrluFhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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