SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c46bf7e21cbf98cb5fb2233e923e22d8295a10b76014db4053ede8f81469e64' 
  AND token = 'NmarnySP7NLhZKxI67Uityr6M4EgfjaOwKTmKdA4N80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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