SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc9762fc27611259a4760e916ff123e9c15e7afbc305cdbfbb09382c9b6b0784' 
  AND token = 'KnpyVYWoUNyKKQPllEfvEPMk3XKvZBOST0VTzvnjR64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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