SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77e9cc903ebdc20d4a392d4ed2409d60ce8dc2a931b054ccf2f6e0ec680e2bbe' 
  AND token = 'cpjYliByMFVAnhGnb5uDqNBY7QRVjxgE+B096lGKpbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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