SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd93d4594596b9b0233a979de9e1ce2c4f10573306cbd14f897fa3fcd9bf9ac26' 
  AND token = 'sPhGlGvrrGTPz1BEkLkWV+VWkY5e4XjQ2KE/zA4c18g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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