SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cadc5966af42979a94dc81fe802fdacfbd2cac67dbe564b383fc09d9fd1ed34f' 
  AND token = 'Yff+CVJuztH+ReKaDyAIKwjEIGhsdbYbH2jGgJHDicg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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