SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef8d48a7251a2a6ea0f37ab234454414ff3e42e2aa465095ef22377c0edbe35e' 
  AND token = 'K1WIAoxxeBEVPciXHfUHJD5nVMu9lNelm6N5EelPQUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00088

JSON explain

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