SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c63b50aa07f93b1d86f23f266aaab6952f28b93bd6d900d64c9d09a0a322eaee' 
  AND token = 'Ycnx5he9RSL9/YYrK8d4Eh3lkj80Hg0Q5FGDdpF7zEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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