SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5df6196c677386f130e0e8ae6b8b9959f2ce946f728779c18acb7750e45dd80a' 
  AND token = 'AL0YxZMlYnwmk/9zJ0VQz3P/IOj3OxnWo0G3b4sVm24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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