SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3eaf54bb48a47ed9fb70e05a82ed08de263863086c5d818c853671c8cf392fcc' 
  AND token = 'x/vB968O4Kpat9WYmHymM1S/3xOCi9kXimZDLP6kaEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}