SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ae20698cf5deb5419776013ff0aff22eed37c18f00c2124b96b88ad29f69cd2' 
  AND token = 'qrlknveSKoLTt+DCj3Uxd5vWahAoUC5zfC2yT/2ikok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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