SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b9228086f947c55aa9dfe5a3bc8a07392467309222f6f470e21137695907e1f' 
  AND token = 'Cq3gr/ZWLWJdbd12mXJbRVlUQgTqhhJfWnsknOMvzMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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