SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26e15baccc39c9dfb88dde082a13c8b968e1e5ed5e875db62f67b4b405482129' 
  AND token = '0OhU4zLNW/HSPk3qgGaA+emCWhF1Sz4JVQNES7KipiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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