SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9a2ae0d5d722ae003e9a770cc244d1cb43543f3872a171ba26984ac81d4f394' 
  AND token = 'do6LQkm13SHT21H6BgqJg4Hxbhx8SGriOMVGloOBjcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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