SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4465ae224aa27448f2b91bcf21da9815fb658a43e56f3029f14c96da88526f9d' 
  AND token = '2wxMFmpgtxgCZSoHCWKuxFqhHYXSl8rLB12KiUaurpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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