SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd61d9dd7eab92410b61a706bd81a55dc90bfb5d171920a8ff537dd31d7b02158' 
  AND token = 'HxkypmcxrPJ8Td0QKc9X1xmzPnlF3jNhvmh1hyx0aV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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