SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba781ff48bf7086ddce2931c649b0ba996bfa5c52b095f2937bc0f416cfd924f' 
  AND token = 'yDwKGSQSgfVpgxlzplXuntOttB+aiZ6P3ITjYXh6h4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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