SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2796374c878e0db1288f22075aba4139b69804621fbae676f9ae0307e4c6116c' 
  AND token = 'fVgwzRKIpjQTZvvioPt7IhDlPpG4u7giJBBzAPZ2ATY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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